title: Hydrogen peroxide spraying alleviates drought stress in soybean plants.
abstract: To ascertain the effect of exogenously applied hydrogen peroxide (H2O2) on drought stress, we examined whether the spraying of soybean leaves with H2O2 would alleviate the symptoms of drought stress. Pre-treatment by spraying leaves with H2O2 delayed foliar wilting caused by drought stress compared to leaves sprayed with distilled water (DW). Additionally, the relative water content of drought-stressed leaves pre-treated with H2O2 was higher than that of leaves pre-treated with DW. Therefore, we analyzed the effect of H2O2 spraying on photosynthetic parameters and on the biosynthesis of oligosaccharides related to water retention in leaves during drought stress. Under conditions of drought stress, the net photosynthetic rate and stomatal conductance of leaves pre-treated with H2O2 were higher than those of leaves pre-treated with DW. In contrast to DW spraying, H2O2 spraying immediately caused an increase in the mRNA levels of d-myo-inositol 3-phosphate synthase 2 (GmMIPS2) and galactinol synthase (GolS), which encode key enzymes for the biosynthesis of oligosaccharides known to help plants tolerate drought stress. In addition, the levels of myo-inositol and galactinol were higher in H2O2-treated leaves than in DW-treated leaves. These results indicated that H2O2 spraying enabled the soybean plant to avoid drought stress through the maintenance of leaf water content, and that this water retention was caused by the promotion of oligosaccharide biosynthesis rather than by rapid stomatal closure.
authors.affiliation: Coastal Bioenvironment Center, Saga University, Karatsu, Saga 840-0021, Japan. f0259@cc.saga-u.ac.jp
authors.forename: Yushi
authors.initials: Y
authors.lastname: Ishibashi
authors.forename: Haruka
authors.initials: H
authors.lastname: Yamaguchi
authors.forename: Takashi
authors.initials: T
authors.lastname: Yuasa
authors.forename: Mari
authors.initials: M
authors.lastname: Iwaya-Inoue
authors.forename: Susumu
authors.initials: S
authors.lastname: Arima
authors.forename: Shao-Hui
authors.initials: SH
authors.lastname: Zheng
mesh_terms: D000336:Aerosols; D004187:Disaccharides / Q000378:metabolism; D055864:Droughts; D005700:Galactosyltransferases / Q000235:genetics; D006861:Hydrogen Peroxide / Q000494:pharmacology*; D007295:Inositol Phosphates / Q000378:metabolism; D019753:Intramolecular Lyases / Q000235:genetics; D010788:Photosynthesis / Q000187:drug effects; D018515:Plant Leaves / Q000187:drug effects / Q000201:enzymology / Q000235:genetics / Q000502:physiology; D010940:Plant Proteins / Q000235:genetics; D054046:Plant Stomata / Q000187:drug effects; D018526:Plant Transpiration / Q000187:drug effects; D012333:RNA, Messenger / Q000235:genetics; D018749:RNA, Plant / Q000235:genetics; D012987:Soil; D013025:Glycine max / Q000187:drug effects* / Q000201:enzymology / Q000235:genetics / Q000502:physiology*; D013312:Stress, Physiological; D014867:Water / Q000032:analysis / Q000502:physiology*
chemical_list: D000336:Aerosols; D004187:Disaccharides; D007295:Inositol Phosphates; D010940:Plant Proteins; D012333:RNA, Messenger; D018749:RNA, Plant; D012987:Soil; D014867:Water; C052128:inositol 3-phosphate; C013536:6 beta-galactinol; D006861:Hydrogen Peroxide; D005700:Galactosyltransferases; C096645:inositol 1-alpha-galactosyltransferase; D019753:Intramolecular Lyases; C105497:D-myo-inositol-3-phosphate synthase